Ever get the feeling you've been cheated?

I'm keeping out of supermarkets. Two quid for a bag for life? If I'm going to spend that kind of money on a plastic carrier, I expect it to last past the autumn.

I've just been cheated enough. Of about 40 or 50 years. And I want it back.

I went to see the nice oncologists at Glasgow's Beatson cancer centre on Tuesday, hoping for my next bumper bag of harsh chemicals to keep the evil twisted part of my DNA which keeps trying to eat my brain in check. Instead I found out that the chemo hasn't been working. Despite a successful second operation in January, the poison pills have failed to stop whatever was left from growing another head and I have a recurrence roughly the size of a Brazil nut.

It seems I may only have three to four months to live.

I would turn 45 this year. Given my generation, my social background and the relative longevity of my family, I was expecting to see my 90s.

I had plans: I wanted to be a published author; I wanted to be a dad; I wanted to grow old with Clare; I wanted us both to travel more extensively than we have. I'd even have quite liked to have finished learning to play the guitar properly. Circumstance is such a swindler.

It isn't fair. But of course it's not – fairness and justice are human

constructs, they don't exist in nature. I can ask the ridiculous question "why me?", but I already know the answer is "why not?"

Not that I believe there's anything to ask the question of, other than the logic and intellect we have evolved. And my lack of faith is a comfort. I'm not afraid of death. It's merely oblivion. There was a time before I was here, and I didn't suffer then. The religious have the foolish idea of vengeful gods and devils to terrify them through such dark times. I may have to eventually succumb to this terrible disease, but I will not succumb to the virus of faith.

I have some time left, and I will make the most of it. Of course I'm afraid of dying, but of the process, not the aftermath. Cancer death can be so cruel and undignified. At least with glioblastoma it seems that there is no pain, no suffocation on pneumonia, no dwindling out of personality into dementia. Eventually the tumour fatigue takes hold and you simply sleep it away. But until then, I fully intend to enjoy myself as much as I can. I will remain me until the end, and I will not waste that time on self-pity and fear. And I will fight with every resource at my disposal. I have a strong mind, and I'm not planning on going anywhere gently.

I have one more chemo option left to me. The prognosis of 12 to 16 weeks is without treatment other than the steroids which keep the effects of swelling under control and keep me feeling relatively well, but I also have the opportunity to spend a night plugged into a drip at the Beatson every three weeks for the foreseeable. That's pretty frequent given the timescales we're talking about and will leave me a bit gubbed for a couple of days each time. But in exchange for that, I get about a 10% chance of doubling the existing estimate.

There's a quality of life judgement to be made there, balancing a little short-term time I can be making the most of against not-very-good odds of slightly longer-term time during which I might not feel exactly lovely, but of which I can also try to make the most.  But I'm a fighter.

So I'm fighting for as much good time as I can get.

As part of that, Clare and I are currently enjoying a weekend break in the Lakes, something we like to do around this time of year. It's lovely here, and they have nice food and beer.

So, making the most of it. I just wish I wasn't also carrying about this poison sac of bereavement and anger in my lower gut. It's heavy and hurts, and gets in the way of my Good Time. Still, I just need to fight that, too.

I'll work out how I do that as soon as  I can.